The invention relates to a process for the manufacture of a drill head comprising a core body with hard, wear-resistant cutting elements or cutters fitted therein and projecting from the surface and consisting in sequence of a (cutting) tip and a shank or shaft.
Such drill heads are known in the prior art, for example, U.S. Pat. No. 2,687,875 and from practical use. Fastened to drilling tools such drill heads are suitable for forming apertures in hard materials or holes and cavities in the earth. For this purpose a drill head is manufactured from a hard steel body in which very precise apertures must be machined; into such an aperture the shank or shaft portion of a cutting element may be inserted with a press fit. This known process of manufacture has hitherto had a restrictive effect on the shape of the shank portion of the cutting element, which has had a cylindrical or similar form. Apart from the expensive machining of the hard core body which is necessary, there is also a practical disadvantage; because of the relatively large external forces acting on these wear-resistant elements, they are prematurely loosened from their cylindrical or tubular mountings so that drilling is impeded or even becomes impossible.